Convertible boring brace



Dec. 22, 1931. L BLAKE CONVERTIBLE BORING BRACE Filed April 5, 1930 2 Sheets-Sheet 1 Dec. 22, 1931, BLAKE 1,837,943

' CONVERTIBLE BORING BRACE Filed.April 3, 9 2 Sheets-Sheet 2 gwuzntot 17. L .1? law? 0 g5)? i I Patented Dec. 22, 1931 PATENT OFFICE DAN L. BLAKE, OF WENATOHEE, WASHINGTON CONVERTIBLE BORING BRAGE Application filed April 3, 1930. Serial No. 441,327.

This invention relates to braces such as are used with bits and the general object of the present invention is to provide a combination brace which may be used for either drilling in a corner where an ordinary straight brace cannot be used or be used in the usual manner.

A further object is to provide a device of this character in which the chuck of the brace is operatively connected to the rotatable section of the brace by a flexible coupling which will permit the handle section to be turned into angular relation to the chuck section and provide means whereby these sections may be held in this position.

A further object is to provide means whereby the crank portion of the handle may be increased or decreased in throw depending upon the size of the hole to be drilled or the necessity of greater or less leverage.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings, wherein Figure 1 is an elevation of a brace constructed in accordance with my invention, the parts being in section;

Figure 2 is a fragmentary sectional view through one of the end sections of the brace showing the inserted metal section;

Figure 3 is a cross section of the brace for supporting the bit at an angle to the rotative portion of the brace;

Figure 4 is an elevation partly in section of the brace shown in Figure 1, but adjusted with the bit in angular relation to the body of the brace;

Referring to these drawings, designates the chuck section of an ordinary brace. I have not attempted to show this in detail, but it will be understood that it is formed to grip the bits to be used in any usual or suitable manner. The rear end of this chuck section is formed with a socket 11. The exterior portion of this chuck section is screwthreaded as at 12 for the reception of a screw-threaded sleeve 13 annularly recessed at its middle as at 14.

Coacting with this chuck is a handle or crank formed of three sections 15, 16 and 17. The section is angular in form and at one reduced in diameter with relation to the remainder of the section 15 and which is adapted to receive and be engaged by the screwthreaded sleeve 13. As shown most clearly in Figure l, the pin 19 extends inward from the wall of the socket 11 and enters a slot formed in the ball 18, this slot as shown clearly in Figure d being formed to extend over a quarter of a circle so that the ball may be rotated in a longitudinal direction from a position where the por ion 20 is in alinement with the socket or is disposed as shown in Figure 1-, out of alinement with the socket and at an angle of relative thereto. The angular shank of the section 15 is hollow as at 21 and longitudinally split as at 22. The end of this section 15 remote from the ball 18 is sli htly reduced in diameter and tapered and exteriorly screw-threaded as at 23. The section 16 at its opposite ends has shank portions 24 extending at right angles to the middle of the section 16, these shank portions being fiat on one side or if desired being many-sided in cross section. One of these shank portions is adapted to be inserted in the bore 21 and the section 15 may be shifted longitudinally upon the shank portion 2a to increase or decrease the throw of the crank. The parts are held in their adjusted positions by means of the interiorly screwthreaded nut 25 which is turned upward over the screw-threads 23 and forces the tangs defined by the slots 22 inward against the shank 2 1. The section 17 at one end carries the usual swiveled knob 26 commonly found in braces of this character, this section 17 being also angularly formed and formed with a bore 21 and is slotted as at 22 and screw threaded as at 23 all as heretofore described. A nut 25 clamps the parts 2% and 17 in adj usted engagement with each other. Thus it will be seen that the crank portion 16 may be adjusted inward or outward relative to the sections 17 and 15 to increase or decrease the radius of the crank.

For the purpose of holding the chuck portion of the brace at an angle of 45 to the longitudinal axis of the ball 18 and neck 18 which is the position of the parts when the brace is to be used for corner drilling, I provide a detachable clamp member 27 having two legs 28. Each leg 28 is formed with resilient jaws 29 at its end which jaws at one end of the brace 27 are adapted to embrace the shank 17 and be disposed in a recess 30 in this shank, and at the other end of the brace 27 are adapted to embrace the sleeve 13 and be disposed within the circumferential recess 14:. By this means the chuck 10 will be held at an angle of 45 relative to the axis of the angular portion of the section 15 as shown in the drawings and the brace may be used for drilling through the corners of walls where an ordinary brace could not possibly be used. I do not wishto be limited to the particular type of flexible coupling between the element 15 and the chuck of the drill as other forms of flexible coupling might be used.

It will be seen that with this invention, the leverage exerted by the handle 16 may be increased or decreased depending upon the size of the hole to be drilled and the resistance offered to the drill. Ordinarily carpenters carry three braces, one for drilling holes in corners, one straight brace with short sweep and another straight brace with longer sweep. My improved brace is designed to take the place of these three different braces.

I claim A convertible brace comprising a chuck section exteriorly screw-threaded and having a socket, a handle section having a ball insertible into said socket and exteriorly screwthreaded adjacent the ball, a pin engaging the ball with the chuck section for common rotation, but permitting the chuck section to be turned at an angle of 45 relative to the handle section, asleeve having screw-threaded engagement with the screw-threads of the chuck section and adapted to be turned to have screw-threaded engagement with the threads of the handle section and thereby to hold the two sections in alinement with each other, the sleeve being circumferentially recessed, and a U-shaped clamp member having clamps at its opposite ends adapted respectively to detachably embrace the sleeve in said recess and adapted to engage the handle section and hold the handle section and the chuck at an angle to each other.

In testimony whereof I hereunto afiix my signature.

DAN L. BLAKE. 

